The use of air fresheners for vehicles has been a growing market in recent years. There are different technologies for this application which are based on the same domestic use technologies. For example, devices with a bottle and a wick, membrane devices, etc., the majority with a clamping element to fix the device to the ventilation screen of the air conditioning system of the vehicle.
A technology which has been growing considerably recently consists of a system which has a solid gel which contains a volatile substance. This system has a minimal construction: an open container in which the gel has been poured prior to being made solid, a peelable barrier sheet to prevent the evaporation of the product prior to the first use and a clamping element.
The clamping element is often placed in the center of the container to allow the device to be assembled in the center of the screen. Thus the container has a central part, usually cylindrical in which the clamping element is fixed. This means that the device is sold with the clamping element unassembled in order to allow the removal of the barrier sheet.
A significant problem with the use of these types of devices based on gel is linked to the fact that the gel progressively contracts when the volatile substance is released. This contraction is not homogenous over the entire volume of the gel since only one side of the gel is exposed to the atmosphere, generally the rear part of the device, that is to say, the part that is oriented towards the ventilation screen. Thus, this side of the gel contracts first, which can cause the bending of the gel in the direction of the screen.
This is critical if the bending is so significant that the gel ends up contacting the plastic ventilation screen, or the dashboard of the vehicle since the most commonly used plastics for manufacturing the screen or the dashboard are selected for the mechanical and aesthetic characteristics thereof, but they have very poor resistance to perfumes.
Therefore, the contact between the gel and the plastic of the vehicle may cause discoloration of the plastic, the separation or the appearance of bubbles or creases in the coating of the plastic. If this occurs, the only solution is to replace the damaged parts which may be expensive.
This phenomenon is made even more difficult to solve because there are a very high number of usage configurations of the product since there are a wide number of designs of the screen, different ways of fixing the device on the same screen and different environmental conditions for the evaporation (heating, air conditions, ultraviolet light system, etc.).
Therefore, the object of the present invention is to provide a device for releasing volatile substances for vehicles having a gel deposit which limits the deformation of the gel during the evaporation.